Moving heaters disposed in a susceptor device in a masked sputtering chamber

ABSTRACT

A susceptor device in a masked sputtering chamber is disclosed. The device of the present invention comprises a susceptor, a lifter and at least one heater. The susceptor, having at least one trench, is coupled with the lifter having at least one rod. The heater is disposed in the trench and coupled with the rod through the access hole at the bottom of the trench. After the sputtering process for forming indium tin oxide (ITO) film is completed, a baking process is applied to the mask in the chamber for converting the amorphous ITO film formed on the mask to polycrystalline ITO film, thereby increasing the life of the mask.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general to a susceptor device. Inparticular, the present invention relates to a susceptor device in amasked sputtering chamber, the application of which increases the lifeof the mask in the chamber.

2. Description of the Related Art

In a conventional sputtering chamber, it is necessary to prevent residuefrom being deposited on the inside wall of the chamber. Normally a masksurrounds the space between the substrate and the target in the chamberto prevent film residue from forming on the inside wall of the chamber.After the sputtering process is performed several times, it is necessaryto remove the mask from the chamber for preventative maintenance (PM).Unfortunately, sputtering equipment can not be used at this time. Thus,production is dependent upon the timing of PM. As well, cleaning themask is expensive thus increasing production costs.

In the sputtering process for fabricating liquid crystal display (LCD)units, it is necessary to deposit indium tin oxide (ITO) on the glasssubstrate, and the described problem occurs when the ITO film forms onthe mask. Since the ITO film is usually amorphous, it peels off the maskdue to weak adhesion and contamination of the chamber takes place. Thus,it is necessary to remove the mask for frequent PM. The problems ofyield and cost previously mentioned are likewise heightened. Theconventional method of solving these problems is, when sputtering is notunderway, to heat the susceptor by means of a heat coil mounted on thebottom of the susceptor. Thus, a baking process is administered to theITO film deposited on the mask. As a result, the ITO film is convertedto polycrystalline ITO film, increasing its adhesion. These measures dogrossly contribute to extending the life of the mask. Unfortunately, thethickness of the susceptor greatly inhibits rapid temperature changes,impacting production by causing lengthy PM sessions, or restricting thefrequency of these sessions, thereby curtailing the efficacy of thesolution.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a susceptor device in amasked sputtering chamber with which the ITO film formed on the maskundergoes a baking process, thereby increasing the life of the mask.

The device of the present invention comprises a susceptor, a lifter andat least one heater. The susceptor has a positioning surface on whichthe substrate is placed, a supported surface opposite the positioningsurface, at least one trench located on the positioning surface, and atleast one access hole through the supported surface from the trench, allof which is disposed in the chamber. The lifter has a supporting sectionto prop up the supported surface and at least one supporting rod, whereone end of the rod is driven by the lifter and the other end passesthrough the access hole moving between a first and second position. Theother end of the rod through the access hole is coupled with at leastone heater. When the other end of the rod is in the first position, theheater is situated in the trench, accommodating the placement of thesubstrate on the positioning surface. In the second position, the heateris raised above the trench for the application of the baking process.Use of the susceptor device in accordance with the present inventionboth enhances the life of the mask and reduces the requirements forproduction-interruptive PM.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention can be more fully understood by reading thesubsequent detailed description in conjunction with the examples andreferences made to the accompanying drawings, wherein:

FIG. 1 is a plane-view diagram showing the susceptor device in asputtering chamber in accordance with the embodiment of the presentinvention;

FIG. 2 is a cross-sectional diagram showing the susceptor device alongthe A—A line in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides a susceptor device in a masked sputteringchamber. The mask surrounds the space between the susceptor and thetarget in the chamber. Its purpose is to prevent atoms from beingdeposited on the inside wall of the chamber and causing contaminationduring the sputtering process in which indium tin oxide (ITO) is appliedto the glass substrate of LCD units. After the completion of thesputtering process, the substrate is removed from the chamber and theamorphous ITO film coating the mask undergoes the baking process withthe result being its conversion to crystalline ITO film.

Refer to FIG. 1 and FIG. 2. FIG. 1 is a plane-view diagram showing thesusceptor device in a sputtering chamber in accordance with theembodiment of the present invention. FIG. 2 is a cross-sectional diagramshowing the susceptor device along the A—A line in FIG. 1. The susceptordevice of the present invention comprises a susceptor 10, a lifter 16and at least one heater 20. The rectangular susceptor 10 is disposed ina sputtering chamber 1, having a positioning surface 101 on which toplace the glass substrate (not shown), a supported surface 102 oppositethe positioning surface 101, four trenches 12 on the positioning surface101 and eight access holes 12 through the supported surface 102 from thetrenches 12. The shapes of the trenches 12 are formed at the edgeportion on the positioning surface 101 of the susceptor 10,respectively, as shown in FIG. 1 In addition, there are two access holes14 formed on the bottom of each trench 12, as shown in FIG. 2.

Referring to FIG. 2, the lifter 16 under the susceptor 10 has asupporting portion 161 to couple with the supported surface 102 to propup the susceptor 10, and eight supporting rods 18. The lifter 16 drivesone end of each rod 18 and the other end of each rod 18 is passedthrough each access hole 14. That is, each of the two supporting rods 18passes through the bottom of each trench 12 from each two access holes14 formed on the bottom of each trench 12, respectively, so as to movebetween the position within the trench 12 and the position above thetrench 12. The position within the trench 12 is the first position andthe position above the trench 12 is the second position. There are fourheaters 20 disposed, one each, in the four trenches 12. The heater 12 isselected from a group consisting of lamp, nickel chrome filament andtungsten filament. Here, the lamp is used in the present invention. Theheater 20 in the trench 12 is coupled with the other end of the rod 18,thereby moving between the first position and the second position usingthe rod 18. When the heater 20 is located at the first position, it isnon-funtional so as to accommodate the placement of the glass substrate(not shown) on the positioning surface 101 of the susceptor 10 for theITO sputtering process.

After performing the ITO sputtering process several times, it can beseen that amorphous ITO film (not shown) formed on the mask (not shown)peels off the mask, causing contamination. At this time, the heater 20is elevated from its first position within the trench to the secondposition by the rod 18 driven by the lifter 16. Baking begins, and themask is heated to a temperature of more than 200° C. The amorphous ITOfilm is thus converted to polycrystalline ITO film, and its adhesion isgreatly enhanced, preventing substrate contamination during thesputtering process. The lifetime of the mask is thus increased due tothe formation of the polycrystalline ITO film, and, at the same time,production is greatly enhanced by the decrease in required PM.

Finally, while the invention has been described by way of example and interms of the preferred embodiment, it is to be understood that theinvention is not limited to the disclosed embodiments. On the contrary,it is intended to cover various modifications and similar arrangementsas would be apparent to those skilled in the art. Therefore, the scopeof the appended claims should be accorded the broadest interpretation soas to encompass all such modifications and similar arrangements.

What is claimed is:
 1. A susceptor device in a masked sputteringchamber, wherein a baking, process is applied to the mask after thesputtering process is completed, comprising: a susceptor, disposed inthe chamber, having a positioning surface on which a substrate isplaced, a supported surface opposite the positioning surface, at leastone trench located on the positioning surface and at least one accesshole through the supported surface from the trench; a lifter having asupporting portion to prop up the supported surface and at least onesupporting rod, wherein one end of the rod is driven by the lifter andthe other end passes through the access hole moving between a firstposition and a second position; and at least one heater coupled with theother end of the rod through the access hole, wherein the heater ispositioned in the trench to accommodate placement of the substrate onthe positioning surface when the other end of the rod is in the firstposition, and the heater is elevated above the trench to bake the maskwhen the other end of the rod is at the second position.
 2. Thesusceptor device as claimed in claim 1, wherein the sputtering processis a sputtering process for indium tin oxide (ITO).
 3. The.susceptor-device as claimed in claim 1, wherein there are four trenchesformed in the susceptor and each trench is disposed with one heater. 4.The susceptor device as claimed in claim 3, wherein the trenches areformed at an edge portion on the positioning surface of the susceptor,respectively.
 5. The susceptor device as claimed in claim 3, wherein theheaters are selected from a group consisting of lamp, nickel chromefilament and tungsten filament.
 6. The susceptor device as claimed inclaim 1, wherein the mask surrounds the susceptor.